Device for bending,coiling,or straightening tubing



- Mai 20, 1969 J'. R. MARTIN DEVICE FOR BENDING, COILING, ORSTRAIGHTENING TUBING Filed June 13. 1966 FIGA .i-I iI-F incl-.2: .l...

INVENTOR. JOHN R. MARTIN ATTORNE S United States Patent 3,444,716 DEVICEFOR BENDING, COILING, 0R STRAIGHTENTNG TUBING John R. Martin, AllenPark, Mich., assignor to Calumet & Hecla, Inc., Allen Park, Mich., acorporation of Michigan Filed June 13, 1966, Ser. No. 557,002 Int. Cl.B21f 3/02 US. Cl. 72-135 9 Claims ABSTRACT OF THE DISCLOSURE The devicecomprises a rigid grooved roll associated with a second roll at leastthe periphery of which is formed of yieldable resilient material.Preferably, the yieldable resilient material is a ring received in aperipheral channel formed in a rigid circular support body. The rollsare adjustable towards and away from each other to vary the amount ofcurvature imparted to or removed from tubing.

It is an object of the present invention to provide a device forbending, coiling or straightening tubing in which the efiectiveness isreadily adjustable.

More specifically it is an object of the present invention to provide atube bending device comprising a relatively small peripherally groovedsteel roller associated with a pressure roller having at least itsperipheral portion formed of a readily distortable resilient materialsuch for example as urethane.

It is a further object of the present invention to provide a device asdescribed in the preceding paragraph in conjunction with means forvarying the spacing between the rollers so as to vary the pressureapplied by the roller comprising yieldable material and thereby to varythe radius of curvature imparted to the tubing.

It is a feature of the present invention to provide tube bendingequipment comprising a rigid relatively small peripherally grooved metalroller and a relatively larger pressure roller having yieldableresilient material disposed around its periphery and rigid means at thesides of the yieldable resilient material confining the material againstlateral displacement.

It is a further feature of the present invention to provide a device asdescribed in the preceding paragraph in which the roller provided withthe yieldable resilient material includes a peripheral groove or channelshaped to provide lateral support to the yieldable resilient materialthereby preventing lateral displacement thereof and provided furtherwith a centrally grooved bottom wall aflording an annular space intowhich the yieldable resilient material is displaced under pressure.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings, illustrating a preferred embodiment of theinvention, wherein:

FIGURE 1 is a diagrammatic elevational view showing the relationshipbetween rollers and tubing.

FIGURE 2 is a side view of the structure shown in FIGURE 1.

FIGURE 3 is a sectional view illustrating adjustable means for mountingone of the rollers.

FIGURE 4 is an enlarged fragmentary sectional view through the rollerprovided with yieldable resilient material.

FIGURE 5 is a fragmentary elevation of an alternative pressure adjustingstructure.

FIGURE 6 is a diagrammatic showing of a plurality of sets of rollersused concurrently.

The device disclosed in the figures may be employed in bending, coilingor straightening tubing by passing the 3,444,716 Patented May 20, 1969tubing between a pair of opposed rollers. One roller 10 is formed ofmetal, such for example as steel, and is provided with a peripheralgroove 12 of semi-circular cross section and conforming to the diameterof the tubing to be operated upon.

Associated with the relatively small metal roller 10 is a pressureroller 14 having the peripheral portion 15 formed of yieldable resilientmaterial. This material is a rubber-like material of medium hardnesshaving for example a hardness in the neighborhood of 70 on a Shoredurometer. A suitable material for this purpose is urethane. The outersurface of the yieldable resilient material may if desired be providedwith a shallow annular groove 16, or this groove may be omitted and theouter surface of the yieldable material may be a truly cylindricalsurface.

In operation one or both of the rollers is driven and the end of a tubeT to be bent is advanced on a horizontal supporting table 17 tointroduce the end of the tubing into the bight between the rollers. Thetable 17 may have a flat upper surface or it may be provided with agroove conforming to the diameter of the tubing, the groove being of adepth not exceeding the radius of the tubing.

In FIGURE 4 the detailed construction of the pressure roller 14 isillustrated. The roller comprises a circular support body 18 having agenerally cylindrical peripheral surface 20 provided intermediate itsedges with an annular relief groove 22. At one edge of the body 18 ispro vided a flange 24. The yieldable resilient ring 26 is provided asillustrated in FIGURE 4 and is retained in position by a support plate28, the peripheral edge of which has the same diameter as the [flange2'4 and is adapted to extend to the outer surface of the yieldable ring26. The plate 28 is attached to the body 18 by suitable means such forexample as screws (not shown).

Referring now to FIGURE 3, there is illustrated mechanism for supportingthe rollers in operative relation, for driving one of the rollers andfor providing adjustment of one roller radially of the other so as tovary the pressure developed by distortion of the yieldable ring andthereby to predetermine the radius of curvature imparted to the tubing.In this figure a support 30 is provided having a pair of upstandingflanges 32 and 34 separated to provide a roller receiving space 36therebetween. The relatively small peripherally grooved metal roller 10is supported on a drive shaft 38 to one end of which is fixed a drivegear 40 in mesh with a pinion 42 driven by suitable means such forexample as a motor (not shown). The relatively large roller 14 issupported on a shaft 44 the ends of which are vertically adjustable inelongated slots 46 formed in the flanges 32 and 34. Adjustment screws 48are provided extending through threaded openings into the slots 46 andthe inner ends of the screws are illustrated as engaging the oppositeends of the shaft 44.

In use the roller 10 is driven in rotation through the gearing 42, 40and the frictional engagement between the rollers causes the pressureroller 14 to rotate with the same surface speed as the small steelroller. The axial spacing between the rollers 10 and 14 is adjusted bysuitable adjustment of the screws 48 and accordingly the deflection ofthe yieldable resilient material of the ring 26 is similarly varied. Thedistortion of the yieldable resilient material applies bending pressureto the portion of the tubing extending to the left of a line joining thecenters of the rollers as seen in FIGURE 1 and this pressure iseffective to bend the tubing. It is found that the tubing is bent to asubstantially uniform radius and this radius is directly controllable byvarying the pressure applied through the adjusting screws 48.

Referring now to FIGURE 5, there is illustrated a modification of thedevice for adjustably supporting a shaft 50 mounting one of the rollersfor adjustment radially with respect to the other. In this embodimentthe ends of the shaft are journaled in blocks 52 slidable vertically inslots 54- provided in support structure such as the flanges 32 and 34seen in FIGURE 3. The blocks 52 are biased upwardly by resilient meanssuch as coil compression Springs 56 the lower ends of which asillustrated may be received in pockets 58. Adjusting screws 60 extendthrough threaded openings 62 in the support structure and engage theupper ends of the blocks 52.

In use the blocks 52 are urged upwardly against the lower ends of theadjusting screws 66 not only by the action of the compression springs 56but also by the yieldable force exerted by the resilient ring 26 aspreviously described.

As the tube passes between the rollers, the flexible ring 26 deflects inthe area of contact with the tube, thus increasing the length of surfacein contact with the tube. This increased length of contact by one rollerand not the other causes the tube to be bent to a definite predetermineddegree with respect to the solid roller. The amount of pressure of theyieldable ring bearing against the tube determines the amount ofdeflection of the yieldable material and thus the amount of bend orcurvature imparted to the tube at the point of roller contact. The tubebeing drawn between the rotating rollers results in this bend beingplaced progressively longitudinally of the tube.

The device can be applied to form coils or any portion thereof, flat orpancake coils, odd shaped coils, or U-bends. It can also be used tostraighten previously coiled or bent metal or to straighten any tubethat requires straightening.

In order to form a tube into various designs, or in order to straightena tube, it may be necessary to have more than one set of rollers. Forexample, two pairs of rollers positioned in different planes in relationto each other will produce helical tubing.

This arrangement is diagrammatically illustrated in FIGURE 6 where oneset of rollers 70 bends the tubing T into a continuous curve which isthen led to a second set of rollers 72 occupying a plane different fromthe plane containing rollers 70 with the result that the tubing afteremerging from the rollers 72 is given a helical configuration.

In the foregoing description reference has been made to the use of aroller having a ring of yieldable resilient material at its peripherywhich is of larger diameter than the rigid roller associated therewith.This is ordinarily the desirable arrangement but in some cases the tworollers may have equal or substantially equal diameters and even in somecases, the rigid roller may be of larger diameter than the rollerprovided with the yieldable peripheral portion.

In FIGURE 1 of the drawing a rigid support 17 has been illustrated anddescribed for supporting a straight section of the tube T as it advancesinto the bight of the rollers. Where the rollers are used forstraightening tubing it is desirable in some cases to provide, inaddition to the support 17, a generally flat or grooved tube supportsimilar to the support 17 at the other side of the rollers.

The advantages of the tube bending device disclosed herein reside in itssimplicity of design, requiring less tooling, and being more versatilein application. More specifically, the use of the pressure roller withthe yieldable resilient peripheral ring shows less tendency to flattentubing during bending, reduces marking of the tube, and provides a muchgreater pulling force on the tube due to the area engaged by theyieldable ring and the resultant high friction.

The drawings and the foregoing specification constitute a description ofthe improved device for bending, coiling or straightening tubing in suchfull, clear, concise and exact terms as to enable any person skilled inthe art to practice the invention, the scope of Which is indicated bythe appended claims.

What I claim as my invention is:

1. A tube coiling device for coiling a length of tube without anyinterior tube supporting means, said device having a roller setcomprising a rigid roller formed in its entirety of rigid material andhaving a peripheral groove of substantially semi-circular cross-sectionhaving a radius substantially equal to the radius of tubing for whichthe device is designed, a pressure roller substantially larger indiameter than said rigid roller comprising a rigid support body havingat its periphery a ring of yieldable resilient material, means forsupporting said rollers at fixed positions with their peripheralportions in pressure contact, means for driving one of the rollers incontinuous rotation, and means for varying the spacing between the axesof said rollers to vary the bending pressure applied to tubing advancedbetween said rollers to vary the radius of bend imparted thereto.

2. A device as defined in claim 1 which comprises a straight supportsurface at the inlet side of said rollers extending generallyperpendicularly to the plane containing the axes of both of saidrollers.

3. A device as defined in claim 1 in which said ring is rubber-likematerial of medium hardness.

4. A device as defined in claim 3 in which said materail has a hardnessin the neighborhood of on a Shore durometer.

5. A device as defined in claim 3 in which said material is urethane.

6. A device as defined in claim 5 in which said material has a hardnessin the neighborhood of 70 on a Shore durometer.

7. A device as defined in claim 1 comprising in addition a second rollerset substantially similar to the first set positioned to receive benttubing from said first set, the second roller set having its rollersoccupying a plane disposed at an angle to the plane occupied by saidfirst roller set.

8. A tube bending device having a roller set comprising a rigid rollerformed in its entirety of rigid material and having a peripheral grooveof substantially semicircular crosssection having a radius substantiallyequal to the radius of tubing for which the device is designed, apressure roller comprising a rigid circular support body having at itsperiphery a ring of yieldable resilient material, means for supportingsaid rollers with their peripheral portions in pressure contact, meansfor driving one of the rollers in rotation, and means for varying thespacing between the axes of said rollers to vary the bending pressureapplied to tubing advanced between said rollers to vary the radius ofbend imparted thereto, the peripherally grooved rigid roller having adiameter substantially less than the diameter of the pressure roller,said circular support body having an annular channel at its periphery inwhich said resilient ring is located, the sides of said channelextending to the outer surface of said ring to confine the ring againstlateral deflection.

9. A device as defined in claim 8 in which said channel has a bottomsurface grooved midway between its edges to provide an annular spaceinwardly of the central por tion of said yieldable ring.

References Cited UNITED STATES PATENTS 3,371,513 3/1968 Achler et al.72166 1,908,373 5/1933 Loepsinger 72166 X 2,310,091 2/1943 Kepler 72l72X 2,335,028 11/1943 Rose et al 72-173 X 2,467,671 4/1949 Hurlburt et al.72-175 2,769,477 11/ 1956 Neer 72--l66 3,195,338 7/1965 Bram 72l45 X3,205,689 9/1965 Joseph 72-146 3,229,489 1/1966 Huet 72166 X 3,279,23410/1966 Ames 72-465 X MILTON S. MEHR, Primary Examiner.

US. Cl. X.R.

